Rockets

Dictionary of American History
COPYRIGHT 2003 The Gale Group Inc.

ROCKETS

ROCKETS. In their most basic form, rockets are uncomplicated machines. They comprise a fuel supply, a combustion chamber in which the fuel is burnt, and a nozzle through which the products of combustion—mostly hot gasses—can escape. Early rockets were little more than tubes closed at one end and filled with gunpowder. They were used for fireworks and for maritime rescue (as signals and carriers of lifelines), but they lacked the power and accuracy to be useful beyond these highly specialized niches. Military interest in gunpowder rockets was sporadic and limited. The British use of them to bombard Fort McHenry, near Baltimore during the War of 1812, for example, did more for American culture (by inspiring Francis Scott Key to write "The Star Spangled Banner") than it did for British military objectives.

Modern rockets emerged between 1920 and 1960 from the confluence of several technological breakthroughs:

more powerful fuels, lighter structural elements, steering mechanisms, onboard guidance systems, and multiple stages. These changes set the stage for the rocket's development, from the late 1950s on, into a range of powerful weapons and a versatile tool for scientific exploration.

The Birth of Modern Rocketry, 1920–1960

Robert H. Goddard was the spiritual father but not the true founder of American rocketry. He tested his first solid-fuel rocket on 7 November 1918 and the world's first liquid-fueled rocket (burning gasoline and liquid oxygen) on 16 March 1926. Trained as a physicist, Goddard produced rockets notable more for innovative design features than for sound engineering. He also feared that rivals might steal his ideas—an obsession that led him to publish few papers and keep potential collaborators at arm's length. His genius was prodigious, but his influence was slight.

The foundations of American rocketry were laid, in a practical sense, by four small groups of scientists and engineers scattered across the country. The first of these groups, the American Rocket Society, was formed as the American Interplanetary Society in 1930 by a group of technically minded New York City science fiction writers (they renamed their group in 1934). Its leading members went on to found Reaction Motors, one of America's first rocket-building companies. A second important group coalesced in the late 1930s around aerodynamics expert Theodore von Karman at the California Institute of Technology(Cal Tech). In time this group gave rise to another early rocket-building firm: Aerojet. A third group, led by naval officer Robert Truax, formed in the late 1930s at the Naval Research Laboratory in Annapolis, Maryland. The fourth group consisted of 115 scientists and engineers from Germany's wartime rocket program, led by the charismatic Wernher von Braun and hired by the U.S. Army to apply their expertise to its nascent rocket-building program. They brought with them boxes of technical documents and scores of V-2 rockets—then the world's most advanced—in various stages of assembly. Reassembling and test-firing the V-2s under the Germans' direction gave army rocket experts their first practical experience with large ballistic missiles.

All four groups worked closely with the military. Von Braun's and Truax's were directly supported by the army and navy, respectively. Von Karman worked closely with General Henry H. "Hap" Arnold, commander of the U. S. Army Air Forces. Reaction Motors supplied the engines for most of the Air Force's experimental rocket planes, including the Bell X-1 that broke the "sound barrier" in 1947. Through their military projects, the rocket designers also made connections with established defense contractors. The foundations of a robust aerospace industry had thus been laid even before the end of World War II.

The rockets that emerged from these collaborations in the late 1940s and early 1950s established the basic design elements used by American rockets for the rest of the century. These included multiple stages (1947), lightweight aluminum rocket bodies that doubled as fuel tanks (1948), and swiveling engines for steering (1949). High-energy kerosene derivatives replaced gasoline and alcohol in liquid-fuel rockets. Research at Cal Tech produced a viscous solid fuel that produced more power and higher reliability than traditional powders. Thiokol Chemical Corporation improved it and by the 1950s had enabled solid-fuel rockets to match the power of liquid-fuel ones. Combined, these features created a new generation of rockets. The first representatives—such as the Vanguard and Jupiter of the late 1950s—carried the first small American satellites into space. Later examples—such as Atlas and Titan of the early 1960s—had the power to carry a nuclear warhead halfway around the world or put a manned spacecraft into orbit.

Refinements and Applications, 1960–2000

President John F. Kennedy's May 1961 call to land a man on the moon "before this decade is out" gave von Braun and his team—then working for the National Aeronautics and Space Administration (NASA)—a chance to develop the largest rockets in history. The result was the Saturn V, which made possible nine lunar missions (six of them landings) between December 1968 and December 1972. Taller than the Statue of Liberty and heavier than a navy destroyer, the Saturn V generated the equivalent of 180 million horsepower at the moment of liftoff. However, the Saturn series was a technological dead end. No branch of the military had a practical use for so large a rocket, and (without the spur of a presidential challenge) the civilian space program could not afford to use them for routine exploration. Experiments with nuclear-powered rockets, pursued in the mid-1960s, were discontinued for similar reasons.

Saturn was, therefore, a typical of American rocket development after 1960. Specialization, rather than a continual push for more power and heavier payloads, was the dominant trend. The navy, for example, developed the Polaris—a solid-fuel missile capable of being carried safely aboard submarines and launched underwater. The air force developed the Minuteman as a supplement to the Atlas and Titan. It was smaller, but (because it used solid fuel) easier to maintain and robust enough to be fired directly from underground "silos." All three armed services also developed compact solid-fuel missiles light enough to be carried by vehicles or even individual soldiers. Heat-seeking and radar-guided missiles had, by the Vietnam War (1964–1975), replaced guns as the principal weapon for air-to-air combat. They also emerged, in the course of that war, as the antiaircraft weapons most feared by combat pilots. Warships, after nearly four centuries serving principally as gun platforms, were redesigned as missile platforms in the 1960s and 1970s. "Wire-guided" missiles, first used in combat in October 1966, gave infantry units and army helicopter crews a combination of mobility, accuracy, and striking power once available only to tanks.

The space shuttle, NASA's followup to the Project Apollo moon landings, defined another line of rocket development. Conceived as a vehicle for cheap, reliable access to space, it was powered by three liquid-fuel engines aboard the winged orbiter and two large solid-fuel boosters jettisoned after launch. Both were designed to be reusable. The orbiter's engines would, according to the design specifications, be usable up to fifty times with only limited refurbishing between flights. The boosters, parachuted into the Atlantic Ocean after launch, would be cleaned, refurbished, and refilled with solid fuel for later reuse. By the early 2000s the shuttle, since becoming operational in 1981, had achieved neither the high flight rates nor the low costs its designers envisioned. Its reusability was, nonetheless, a significant achievement in a field where, for centuries, all rockets had been designed as disposable, single-use machines.

rocket (in aeronautics)

The Columbia Encyclopedia, 6th ed.

Copyright The Columbia University Press

rocket, any vehicle propelled by ejection of the gases produced by combustion of self-contained propellants. Rockets are used in fireworks, as military weapons, and in scientific applications such as space exploration.

Rocket Propulsion

The force acting on a rocket, called its thrust, is equal to the mass ejected per second times the velocity of the expelled gases. This force can be understood in terms of Newton's third law of motion, which states that for every action there is an equal and opposite reaction. In the case of a rocket, the action is the backward-streaming flow of gas and the reaction is the forward motion of the rocket. Another way of understanding rocket propulsion is to realize that tremendous pressure is exerted on the walls of the combustion chamber except where the gas exits at the rear; the resulting unbalanced force on the front interior wall of the chamber pushes the rocket forward. A common misconception, before space exploration pointed up its obvious fallacy, holds that a rocket accelerates by pushing on the atmosphere behind it. Actually, a rocket operates more efficiently in outer space, since there is no atmospheric friction to impede its motion.

Rocket Design

The key elements in designing a rocket are the propulsion system, which includes the propellant and the exit nozzle, and determining the number of stages required to lift the intended payload. Rocket navigation is usually based on inertial guidance; internal gyroscopes are used to detect changes in the position and direction of the rocket.

Rocket Propellants

The most vital component of any rocket is the propellant, which accounts for 90% to 95% of the rocket's total weight. A propellant consists of two elements, a fuel and an oxidant; engines that are based on the action-reaction principle and that use air instead of carrying their own oxidant are properly called jets. Propellants in use today include both liquefied gases, which are more powerful, and solid explosives, which are more reliable. The chemical energy of the propellants is released in the form of heat in the combustion chamber.

A typical liquid engine uses hydrogen as fuel and oxygen as oxidant; a typical solid propellant is nitroglycerine. In the liquid engine, the fuel and oxidant are stored separately at extremely low temperatures; in the solid engine, the fuel and oxidant are intimately mixed and loaded directly into the combustion chamber. A solid engine requires an ignition system, as does a liquid engine if the propellants do not ignite spontaneously on contact.

The efficiency of a rocket engine is defined as the percentage of the propellant's chemical energy that is converted into kinetic energy of the vehicle. During the first few seconds after liftoff, a rocket is extremely inefficient, for at least two unavoidable reasons: High power consumption is required to overcome the inertia of the nearly motionless mass of the fully fueled rocket; and in the lower atmosphere, power is wasted overcoming air resistance. Once the rocket gains altitude, however, it becomes more efficient. as the trajectory, at first vertical, curves into a suborbital arc or into the desired orbit.

Although all known rockets currently in use derive their energy from chemical reactions, more exotic propulsion systems are being considered. In ion propulsion, a plasma (ionized gas consisting of a mixture of positively charged atoms and negatively charged electrons) would be created by an electric discharge and then expelled by an electric field. The engine could provide a low thrust efficiently for long periods; on a lengthy flight this would produce very high velocities, so that if there is ever a trip to the outer planets an ion drive might be used. Deep Space 1, a space probe launched in 1998 to test new technologies, was propelled intermittently by an ion engine. Even nuclear power has been considered for propulsion; in fact, a nuclear ramjet was developed in the early 1960s before it was realized that because the exhaust gases would be highly radioactive such a drive could never be used in earth's atmosphere.

Design of the Exit Nozzle

A critical element in all rockets is the design of the exit nozzle, which must be shaped to obtain maximum energy from the exhaust gases moving through it. The nozzle usually converges to a narrow throat, then diverges to create a form which shapes the hypersonic flow of exhaust gas most efficiently. The walls of the combustion chamber and nozzle must be cooled to protect them against the heat of the escaping gases, whose temperature may be as high as 3,000°C—above the melting point of any metal or alloy.

Staging of Rockets

Although early rockets had only one stage, it was early recognized that no single-stage rocket can reach orbital velocity (5 mi/8 km per sec) or the earth's escape velocity (7 mi/11 km per sec). Hence multistage rockets, such as the two-stage Atlas-Centaur or the three-stage Saturn V, became necessary for space exploration. In these systems, two or more rockets are assembled in tandem and ignited in turn; once the lower stage's fuel is exhausted, it detaches and falls back to earth. Soviet systems clustered several rockets together, operated simultaneously, to obtain a large initial thrust.

Development of Rockets

The invention of the rocket is generally ascribed to the Chinese, who as early as AD 1000 stuffed gunpowder into sections of bamboo tubing to make military weapons of considerable effectiveness. The 13th-century English monk Roger Bacon introduced to Europe an improved form of gunpowder, which enabled rockets to become incendiary projectiles with a relatively long range. Rockets subsequently became a common if unreliable weapon. Major progress in design resulted from the work of William Congreve, an English artillery expert, who built a 20-lb (9-kg) rocket capable of traveling up to 2 mi (3 km). In the late 19th cent., the Austrian physicist Ernst Mach gave serious theoretical consideration to supersonic speeds and predicted the shock wave that causes sonic boom.

The astronautical use of rockets was cogently argued in the beginning of the 20th cent. by the Russian Konstantin E. Tsiolkovsky, who is sometimes called the
"father of astronautics."
He pointed out that a rocket can operate in a vacuum and suggested that multistage liquid-fuel rockets could escape the earth's gravitation. The greatest name in American rocketry is Robert H. Goddard, whose pamphlet A Method for Reaching Extreme Altitudes anticipated nearly all modern developments. Goddard launched the first liquid-fuel rocket in 1926 and demonstrated that rockets could be used to carry scientific apparatus into the upper atmosphere. His work found its most receptive audience in Germany. During World War II, a German team under Wernher von Braun developed the V-2 rocket, which was the first long-range guided missile. The V-2 had a range greater than 200 mi (322 km) and reached velocities of 3,500 mi (5,600 km) per hr.

After the war, rocket research in the United States and the Soviet Union intensified, leading to the development first of intercontinental ballistic missiles and then of modern spacecraft. Important U.S. rockets have included the Redstone, Jupiter, Atlas, Titan, Agena, Centaur, and Saturn carriers. Saturn V, the largest rocket ever assembled, developed 7.5 million lb (3.4 million kg) of thrust. A three-stage rocket, it stood 300 ft (91 m) high exclusive of payload and with the Apollo delivered a payload of 44 tons to the moon. The space shuttle, or STS (1981–2011), had main engines that used liquid propellant and boosters that were solid-fuel rockets.

Rockets presently being used to launch manned and unmanned missions into space include the Brazilian VSV-30; the Chinese Long March 2C, 2E, and 2F; the European Space Agency's Ariane 5 series and Vega; the Indian PSLV (Polar Satellite Launch Vehicle); the Israeli Shavit 2; the Russian Soyuz U, FG, and 2 and Proton K and M; the Japanese H-2A and Epsilon; the South Korean–Russian KSLV-1; the U.S. Athena 1 and 2, Taurus, Titan 2 and 4B, Delta 2, 3, and 4, and Atlas 2 ,3, and 5; and the multinational, private Sea Launch Zenit-3SL, which uses a converted oil platform located some 1,400 mi (2,250 km) southeast of Hawaii. The Ares I, a two-stage NASA rocket designed to replace the STS as a launch vehicle on manned missions, underwent its first test flight in 2009. Space Exploration Technologies' (SpaceX) two-stage Falcon 9, which is now used to launch the Dragon resupply capsule to the International Space Station, had its first successful test in 2010. Antares, a two-stage rocket using Russian and U.S. technology that was developed by Orbital Sciences Corp. for space station resupply, made its first test flight in 2013.

Rockets

Space Sciences
COPYRIGHT 2002 The Gale Group Inc.

Rockets

Rockets are machines propelled by one or more engines especially designed to travel through space. Rocket propulsion results from ejecting fuel backward with as much momentum as possible. One example is a firecracker that misfires and fizzles across the sidewalk. Currently, most rockets use a solid or liquid propellant that relies on a chemical reaction between fuel and oxidizer for thrust. Although chemical rockets can develop great thrust, they are not capable of lengthy operation. To overcome this drawback, research has been conducted on rockets that use different types of chemicals, or reactants. One type of nonchemical rocket is powered by ion propulsion . These rockets turn fuel into plasma and eject the ions to create thrust. Nuclear rockets that use a nuclear reactor to heat and eject fuel are still at the experimental stage. Scientists have also outlined schemes for fusion pulse rockets, solar sail rockets, and photon rockets.

From "Fire Arrows" to Modern Rocketry

The Chinese were probably the first to use rockets. In 1232 C.E. they defeated a Mongol invasion using a strange weapon called "fire arrows." Filled with an explosive combination of saltpeter and black powder, these were the primitive ancestors of rockets. Later, this new weapon was carried as far as the Near East and Europe. By the sixteenth century, Europeans had taken the lead in exploiting the potential of rockets in warfare.

Rapid progress in military rocketry was made in the nineteenth century. Over 25,000 rockets developed by British artillery officer William Congrieve were launched against Copenhagen, Denmark, in 1807. The same type of rocket was immortalized as "the rocket's red glare" in "The Star-Spangled Banner." Beyond their martial applications, recognition of the potential of rockets in spaceflight began to emerge in the late nineteenth and early twentieth centuries through individuals who were to have a profound impact on the coming space age.

In Russia, the writings of Konstantin Tsiolkovsky greatly influenced many rocket pioneers. Robert H. Goddard, the father of rocketry in America, discovered, as Tsiolkovsky had, that the combination of liquid oxygen and liquid hydrogen would make an ideal rocket propellant. In March 1926,
a 4-meter-tall (13-foot-tall) projectile, the world's first liquid-propellant rocket, was launched from the Goddard family farm in Massachusetts. Later, Goddard set up a facility in New Mexico, where, in 1935, he launched a sophisticated rocket stabilized by gyroscopes and cooled by frigid propel-lant—features common to all modern chemical rockets.

As Goddard labored in the desert, rocket trailblazer Hermann Oberth proposed to the German Army the development of liquid-fueled, long-range rockets. During World War II (1939-1945), Oberth worked together with Wernher von Braun to develop the V-2 rocket for the Germans. On October 3, 1942, a V-2 was launched from Peenemunde on the Baltic coast and reached the edge of space—an altitude of 85 kilometers (53 miles)—becoming the first rocket to do so. After the war, captured V-2s were brought to the United States and Soviet Union and became the basis for postwar rocket research in both countries. The first major development in postwar rocket technology was the concept of multiple stages in which the rocket's
first stage reaches its peak altitude and the second stage is "launched" from the first stage closer to space. This concept is used today on all major launch vehicles, with three-and four-stage rockets not uncommon.

The Origin of Today's Rockets

In the 1950s, von Braun and his "Rocket Team," many of whom had immigrated to the United States, continued their work on multistage rockets near Huntsville, Alabama. There they developed the Jupiter rocket, which
evolved into the Redstone launch vehicle, which sent the first two U.S. astronauts into space. Meanwhile, in the Soviet Union, a team headed by Sergei Korolev developed the R-7 ("Semyorka") rocket, which launched the first artificial satellite, Sputnik 1, in October 1957, and the first man and woman into orbit.

Throughout the late 1950s and early 1960s, the United States developed a series of intercontinental ballistic missiles—Atlas, Thor, and Titan—that would play key roles in both piloted and unpiloted space missions. The Atlas was used to launch Mercury astronauts and satellites into orbit. The Thor gradually evolved into the highly versatile Delta series of rockets, which have launched a large number of National Aeronautics and Space Administration (NASA) planetary missions since the late 1960s. In its various subtypes, the Titan continues to serve both NASA and the U.S. Air Force as a heavy launcher for planetary probes and reconnaissance satellites.

While these vehicles are descendents of military rockets, the Saturn series of launch vehicles, the most powerful ever built by the United States, was developed expressly for the Apollo Moon program. The smaller Saturn 1B was used for the first crewed Apollo mission in 1968 and later lifted all three crews to the Skylab space station. The Saturn V, standing 117 meters (384 feet) tall, powered all Apollo missions to the Moon from 1968 to 1972. The Soviets also developed a series of advanced rockets, such as the Soyuz and Proton, but their "Moon rocket," the N-1, never successfully flew.

The space shuttle marked a radical departure from previous "expendable" rockets. The winged shuttle orbiter, flanked by two solid-propellant boosters, was designed to be reused dozens of times. While many rockets, such as the shuttle, are owned and operated by government, the commercial launch industry had grown enormously since the 1970s and become more international. Today, the International Launch Services company provides launch services on the American Atlas II, III, and V and the Russian Proton vehicles to customers worldwide. Meanwhile, the Boeing Company launches the Delta II, III, and IV and is a partner in Sea Launch, which launches Zenit rockets. Arianespace, a European consortium, is also a major player in the commercial launch industry, producing Ariane 4 and 5 rockets.

The history of rocketry is a long one, and rockets will continue to play important roles in commerce, science, and defense.

Rocketry

Rocketry

The Chinese, in the second century b.c.e., were the first to make simple rockets that used gunpowder for fuel. These simple rockets were fireworks that were used for religious ceremonies. The idea of fireworks soon took on a military usage. Rocket motors were attached to arrows, to greatly extend their range. The same principles that made the rocket arrows fly has allowed people to go to the moon, launch satellites, fly the space shuttle, and even launch rockets that have bowling balls as nose cones. Rocket launches can be seen at Tripoli Rocketry Association and National Association of Rocketry launches throughout the United States. One can see small rockets as well as rockets taller than 14 feet (4.3 meters) being launched.

Rockets fly because of Newton's Third Law of Motion: for every action there is an equal and opposite reaction. Hot gases are produced from the burning of fuel in the rocket motor. The gases push against the inside of the rocket motor as they expand. The hot gas is forced out of the rocket, creating an action force. This creates a reaction force that moves the rocket in the opposite direction. The same thing happens when the end of an inflated balloon is released: the gas escapes in one direction, and the balloon moves in the opposite one.

Until the twentieth century, rockets were small. They were used for firework displays, weapons, to send life lines to ships at sea, and to send signals. Scientists such as Robert Goddard, Konstantin Eduardovich Tsiolkovsky, Hermann Oberth, and Wernher von Braun developed the science and technology that allowed large rockets to fly. In doing so, they developed the science that allowed human space travel.

Goddard realized the potential of rockets and space flight. His analysis of liquid-fuel rocket motors and rocket motors with adjustable thrust, as well as his analysis that rockets could work in space, allowed for the development of today's large rockets. Goddard holds close to seventy patents in rocketry.

In 1903 Konstantin Eduardovich Tsiolkovsky proposed using liquid propellants in rockets, and in 1929 he proposed using multistage rockets as a means of space travel. Hermann Oberth showed that liquid fuels provide a better source of energy for space flight than solid fuels. He worked with young German engineer von Braun to test liquid-fuel motors. Motors were tested in the early 1930s by tossing lit gasoline-soaked rags under a rocket motor, running for cover, and then opening the valve.

Von Braun started to develop rockets for the German army in 1932. He worked in the secret rocket laboratory in Peenemünde, in northeast Germany. He developed the V2 rocket, which served as a guide to start the space programs in the United States and the Soviet Union. This rocket was about 46 feet (14 meters) long and could carry a 2,200-pound (998-kilogram) payload of explosives at speeds of up to 3,500 miles (5,633 kilometers) per hour. Germany first launched the V2 rocket as a weapon of war at Paris on September 6, 1944, and rocket attacks on Britain followed. At the war's end, in 1945, the United States shipped home 100 V2 rockets along with many of the best rocket scientists from Peenemünde. Most of these rockets were launched for scientific research in White Sands, New Mexico. Von Braun spent fifteen years developing missiles for the United States military. He was transferred to NASA in 1960 with a mandate to develop the Saturn rocket, the rocket that went to the moon with the Apollo program.

The world of rocketry changed dramatically on October 4, 1957. The Soviet Union launched Sputnik to an orbit 340 miles (547 kilometers) high.

The satellite circled Earth, sending back a beeping sound that amazed the world. In 1958 the United States successfully launched the 31-pound (14-kilogram) Explorer satellite into space for the first time.

In 1961 humans first reached outer space, when Soviet cosmonaut Yury Gagarin flew for 60 minutes in Vostok 1. On May 5, 1961, Alan Shepard Jr. became the first U.S. astronaut to fly in space. Shepard's Project Mercury flight lasted 15 minutes. John Glenn became the first American astronaut to circle Earth, on February 20, 1962.

Project Gemini launched a capsule for two astronauts. Gemini's ten flights provided experiences with space walks, docking, weightless conditions, and spacecraft recovery that made the Apollo missions to the moon possible.

On July 20, 1969, Neil Armstrong and Buzz Aldrin landed on the moon, where they collected soil and rock samples, took pictures, and performed experiments.

In 1973 astronauts first spent long missions in space on Skylab. This space station enabled experimentation and long stays in space. In 1981 Columbia, the first reusable spacecraft, was launched.

Fuels used in the solid-fuel rockets are a mixture of aluminum metal and ammonium perchlorate. This fuel is used to power the space shuttle boosters. It also powers amateur rockets flown at Tripoli Rocketry Association and National Association of Rocketry launches.

Engines on the space shuttle also burn a mixture of hydrogen and oxygen. The hydrogen and oxygen are compressed and cooled to a liquid in the main fuel tank. When they burn to form water, the combustion is so complete that it often does not look like the motor is burning. Liquid-fuel motors may also burn combinations of kerosene and liquid oxygen. Hybrid motors, using a liquid and solid fuel, are used in amateur rocketry. The fuel

is solid cellulose, and the liquid oxidizer is nitrous oxide (N2O). The hybrid motors are advantageous, as they have a lower cost per flight than does a solid fuel motor.

NASA's Lewis Research Center is applying new battery technology with space flights. Lithium-ion batteries are flat batteries that are connected in series to obtain the required voltage . They are more efficient and weigh much less than the rechargeable NiCd batteries. They do not use lithium metal and do not require liquid; instead, they use a solid polymer electrode. Even when subjected to high pressure or shorts, the batteries do not explode. Possible spin-off uses include powering cell phones, laptop computers, and electric vehicles.

rocket

rock·et1
/ ˈräkit/
•
n.
a cylindrical projectile that can be propelled to a great height or distance by the combustion of its contents, used typically as a firework or signal. ∎
(also rock·et en·gine or rock·et mo·tor)
an engine operating on the same principle, providing thrust as in a jet engine but without depending on the intake of air for combustion, an oxidizer being carried on board along with the fuel.
∎
an elongated rocket-propelled missile or spacecraft.
∎
used, esp. in similes and comparisons, to refer to a person or thing that moves very fast or to an action that is done with great force:
she shot out of her chair like a rocket.•
v.
(rock·et·ed
, rock·et·ing
)
1. [intr.]
(of an amount, price, etc.) increase very rapidly and suddenly:
sales of milk in supermarkets are rocketing |
[as adj.] (rocketing)
rocketing prices. ∎
move or progress very rapidly:
the cab rocketed down a ramphe rocketed to national stardom. ∎ [tr.]
cause to move or progress very rapidly:
she showed the kind of form that rocketed her to the semifinals last year.2. [tr.]
attack with rocket-propelled missiles:
the city was rocketed and bombed from the air.DERIVATIVES:rock·et·like
/ -ˌlīk/ adj.rock·et2 •
n.
(also garden rocket or salad rocket)
an edible Mediterranean plant (Eruca vesicaria subsp. sativa) of the cabbage family, sometimes eaten in salads. ∎
used in names of other fast-growing plants of this family, e.g.,
dame's rocket.

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rocket

rocket Slender, tapering missile or craft powered by a rocket engine. Most of its volume contains fuel; the remainder is the payload (such as an explosive, scientific instruments, or a spacecraft). Liquid-fuelled rockets use a fuel (such as liquid hydrogen) and an oxidizer (usually liquid oxygen), which burn together in the engine. Solid-fuelled rockets have both fuel and oxidizer in a solid mixture. A single-stage rocket has one fuel load, or several that are used simultaneously. A multi-stage rocket has several fuel loads, which are ignited singly in succession as the preceding one burns out. Because rocket engines carry their own fuel and oxidizer, they can operate in outer space where there is no atmosphere. They gain thrust from the reaction (referred to in the third of Newton's laws of motion) produced by rapid, continuous output of exhaust gases. Chemical rocket engines are powered by solid or liquid propellants that are burned in a combustion chamber. The propellants are expelled at supersonic velocity from the exhaust nozzle.

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rocket

rocket2 cylindrical paper or metal case designed to be projected on ignition of explosive contents. XVII. — (O)F. roquette — It. rocchetto, dim. of roccaROCK3; so called from the cylindrical form. Hence vb. XIX.

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